The document provides an overview of the animal kingdom, including characteristics of animals, different phyla of invertebrates, and evolutionary trends seen across animal groups. It describes the basic characteristics of animals, such as being eukaryotic, multicellular, and heterotrophic. It then covers several invertebrate phyla in more detail, including porifera (sponges), cnidaria (jellyfish and corals), platyhelminthes (flatworms), nematoda (roundworms), annelida (segmented worms), and mollusca (mollusks). Finally, it discusses evolutionary trends seen across animal groups involving body organization, symmetry, and development.

1. THETHE
ANIMALANIMAL
KINGDOMKINGDOM

3. Characteristics ofCharacteristics of
AnimalsAnimals

4. Basic CharacteristicsBasic Characteristics
 EukaryoticEukaryotic
 MulticellularMulticellular
 Cell specialization?Cell specialization?
 HeterotrophicHeterotrophic
 Move to food vs. catchMove to food vs. catch
foodfood
 No cell wallsNo cell walls
 Cell mobilityCell mobility
 LocomotionLocomotion

5. InvertebratesInvertebrates
 34 phyla34 phyla
 We’ll cover about elevenWe’ll cover about eleven
 No backboneNo backbone
 Land? Small (no support)Land? Small (no support)
 Ocean? Small or largeOcean? Small or large
 Largest structure on theLargest structure on the
planet built by animals?planet built by animals?

6. VertebratesVertebrates
 1 phylum1 phylum
 Internal skeletonInternal skeleton
 CraniumCranium
 BackboneBackbone
 Nerve chordNerve chord
 Larger sizeLarger size

7. Animal BehaviorsAnimal Behaviors
 FeedingFeeding
 RespirationRespiration
 CirculationCirculation
 GrowthGrowth
 ExcretionExcretion
 ResponseResponse
 ReproductionReproduction

8. Animal Body SystemsAnimal Body Systems

9. SupportSupport
 Provides frameworkProvides framework
for movementfor movement
 Hydrostatic skeletonHydrostatic skeleton
 ExoskeletonExoskeleton
 EndoskeletonEndoskeleton

10. Digestion and ExcretionDigestion and Excretion
 Extracts energyExtracts energy
 None in single-celledNone in single-celled
organismsorganisms
 Gastrovascular cavityGastrovascular cavity
(one opening)(one opening)
 Digestive tract (twoDigestive tract (two
openings)openings)

11. Nervous SystemNervous System
 Carries information;Carries information;
coordinates behaviorscoordinates behaviors
 Nerve netNerve net
 GangliaGanglia
 BrainBrain
 Special sensorySpecial sensory
cells/organscells/organs

12. Respiration and CirculationRespiration and Circulation
 Lungs, gills, etc.Lungs, gills, etc.
 Larger organismsLarger organisms
require circulatoryrequire circulatory
systemssystems
 Open vs. closedOpen vs. closed
circulatory systemscirculatory systems

13. ReproductionReproduction
 AsexualAsexual
 Examples: budding,Examples: budding,
new limbs, etc.new limbs, etc.
 SexualSexual
 Union of gametesUnion of gametes
produced in sexproduced in sex
organsorgans
 Some organisms useSome organisms use
bothboth

14. Evolutionary TrendsEvolutionary Trends

15. Directional TerminologyDirectional Terminology
 Anterior / PosteriorAnterior / Posterior
 Dorsal / VentralDorsal / Ventral
 LateralLateral
 Proximal / DistalProximal / Distal

16. Cells and TissuesCells and Tissues
 CellsCells 
TissuesTissues 
OrgansOrgans 
Organ SystemsOrgan Systems 
OrganismsOrganisms 
PopulationsPopulations
 Tissues: groups ofTissues: groups of
similarly-specializedsimilarly-specialized
cellscells

17. SymmetrySymmetry
 No symmetryNo symmetry
 Radial SymmetryRadial Symmetry
 Pentamerous SymmetryPentamerous Symmetry
 Bilateral SymmetryBilateral Symmetry

18. Bilateral SymmetryBilateral Symmetry

19. CephalizationCephalization
 AnteriorAnterior
grouping ofgrouping of
nerves andnerves and
sensorysensory
structuresstructures

20. Body SegmentationBody Segmentation
 Repeating, similar unitsRepeating, similar units
 In most complex animals,In most complex animals,
segmentation only appears duringsegmentation only appears during
early developmentearly development
 Evolutionary benefitsEvolutionary benefits
 Most segments serve a specificMost segments serve a specific
purposepurpose
 Mobility and flexibilityMobility and flexibility

21.  Zygote – union ofZygote – union of
sperm/eggsperm/egg
 Cleavage – division ofCleavage – division of
zygote cellszygote cells
 Blastula – hollow ball ofBlastula – hollow ball of
embryonic cellsembryonic cells
 Blastopore – “pocket”Blastopore – “pocket”
that forms in cellsthat forms in cells
Embryonic DevelopmentEmbryonic Development

22. Embryonic DevelopmentEmbryonic Development
 Gut develops in one ofGut develops in one of
two ways:two ways:
 Protostomes –Protostomes –
blastopore becomesblastopore becomes
mouthmouth
 Deuterostomes –Deuterostomes –
blastopore becomesblastopore becomes
anusanus

23. Embryonic DevelopmentEmbryonic Development
 Three embryonic tissue layersThree embryonic tissue layers
in most organisms, which givein most organisms, which give
rise to specific tissues:rise to specific tissues:
 Ectoderm (skin, nervousEctoderm (skin, nervous
system)system)
 Mesoderm (skeleton, muscles,Mesoderm (skeleton, muscles,
circulatory system)circulatory system)
 Endoderm (glands, liver, gut,Endoderm (glands, liver, gut,
lungs)lungs)

24. CoelomCoelom
 Internal body cavityInternal body cavity
that houses organsthat houses organs
 Cushions organs andCushions organs and
assists withassists with
movementmovement
 Some organisms areSome organisms are
consideredconsidered
“pseudocoelomates”“pseudocoelomates”

25. In Review: Complex AnimalsIn Review: Complex Animals
 Cell specializationCell specialization
 CephalizationCephalization
 Bilateral SymmetryBilateral Symmetry
 SegmentationSegmentation
 DeuterostomesDeuterostomes
 Three tissue layersThree tissue layers
 CoelomateCoelomate

26. InvertebratesInvertebrates

27. InvertebratesInvertebrates

28. What to Remember About Each PhylumWhat to Remember About Each Phylum
 Symmetry?Symmetry?
 Cephalization?Cephalization?
 Nervous, circulatory, skeletal,Nervous, circulatory, skeletal,
digestive, and other systemsdigestive, and other systems
 Specific characteristicsSpecific characteristics
 ExamplesExamples

29. Phylum PoriferaPhylum Porifera

30. PoriferaPorifera
 ““sponges”sponges”
 Feed, excrete andFeed, excrete and
undergo respirationundergo respiration
by passing waterby passing water
through theirthrough their
bodiesbodies
 ChoanocytesChoanocytes
 OsculumOsculum

31. PoriferaPorifera
 No symmetryNo symmetry
 No nervous systemNo nervous system
 No extracellular digestionNo extracellular digestion
 Size ranges fromSize ranges from
centimeters to meterscentimeters to meters
 Can reproduce sexually orCan reproduce sexually or
asexually (budding)asexually (budding)
 Most are hermaphroditicMost are hermaphroditic

32. PoriferaPorifera
 Cells not organized into tissuesCells not organized into tissues
 Classified according to theirClassified according to their
skeleton (of spicules or spongin)skeleton (of spicules or spongin)

33. PoriferaPorifera

34. PoriferaPorifera
 Mutualistic relationshipsMutualistic relationships
with other organisms,with other organisms,
like this sponge crablike this sponge crab

35. Phylum CnidariaPhylum Cnidaria

36. CnidariaCnidaria
 jellyfish, hydras, seajellyfish, hydras, sea
anemones, coralsanemones, corals
 CarnivorousCarnivorous
 Radial symmetryRadial symmetry
 Gastrovascular cavityGastrovascular cavity
(one opening)(one opening)

37. Cnidaria
 Two possible body forms:
 Medusa (free-floating,
sexually reproducing)
 Polyp (sedentary,
asexual)
 Two tissue layers
(epidermis and
gastrodermis) with jelly-
like mesoglea in-between

38. CnidariaCnidaria
 Stinging cells calledStinging cells called
cnidocytescnidocytes
 Cnidocytes containCnidocytes contain
nematocysts, poison-nematocysts, poison-
filled stingersfilled stingers
 Hydrostatic skeletonHydrostatic skeleton
 Nerve NetNerve Net
 Movement byMovement by
muscular contractionmuscular contraction

39. CnidariaCnidaria
 Mutualistic relationshipMutualistic relationship
with algaewith algae
 Coral bleachingCoral bleaching

40. FlatwormsFlatworms
Phylum PlatyhelminthesPhylum Platyhelminthes

41. PlatyhelminthesPlatyhelminthes
 Soft, flattened wormsSoft, flattened worms
 Internal organsInternal organs
 Bilateral symmetryBilateral symmetry
 CephalizationCephalization
 No coelomNo coelom
 Muscle tissuesMuscle tissues

42. PlatyhelminthesPlatyhelminthes
 Feeding: carnivores,Feeding: carnivores,
scavengers, parasitesscavengers, parasites
 Mouth found on undersideMouth found on underside
 Invert pharynx to feedInvert pharynx to feed
 Exception: TapewormsException: Tapeworms
absorb nutrients throughabsorb nutrients through
the body wallthe body wall
 No need for circulatoryNo need for circulatory
systemsystem

43. PlatyhelminthesPlatyhelminthes

44. PlatyhelminthesPlatyhelminthes
 Much more complexMuch more complex
nervous system thannervous system than
CnidariaCnidaria
 More advancedMore advanced
reproductive systemreproductive system
 Planaria are “cross-eyed”Planaria are “cross-eyed”
flatworms that live inflatworms that live in
nearby streamsnearby streams
 Eyespots sense lightEyespots sense light

45. Platyhelminthes
 Example: Schistosoma
 Cause schistosomiasis (second most devastating
parasitic disease – 200,000,000 infected)
 Larvae bore through skin and mature
 Females lay eggs in blood vessals
 Eggs block blood vessals, damaging organs
 Eggs deposited in feces
 Larvae infect snail and reproduce asexually

46. RoundwormsRoundworms
Phylum NematodaPhylum Nematoda

47. NematodaNematoda
 Two openings – mouthTwo openings – mouth
and anusand anus
 Simplest animals withSimplest animals with
coelom (actually acoelom (actually a
pseudocoelom), allowingpseudocoelom), allowing
better coordination ofbetter coordination of
musclesmuscles
 Some carnivorous, some,Some carnivorous, some,
detritivores, somedetritivores, some
parasiticparasitic

48. NematodaNematoda
 Separate sexesSeparate sexes
 Internal fluid actsInternal fluid acts
as a simpleas a simple
circulatory systemcirculatory system

49. NematodaNematoda
 Although lessAlthough less
common thancommon than
free-livingfree-living
nematodes,nematodes,
some aresome are
parasitic andparasitic and
cause diseasescause diseases
in humansin humans

50. Segmented WormsSegmented Worms
Phylum AnnelidaPhylum Annelida

51. AnnelidaAnnelida
 70% live in water70% live in water
 Includes most commonIncludes most common
earthworms and leechesearthworms and leeches
 Segmented: many organsSegmented: many organs
repeat in each segmentrepeat in each segment
 True coelomTrue coelom

52. AnnelidaAnnelida
 Many types of feeding:Many types of feeding:
filter feeders, carnivores,filter feeders, carnivores,
parasitesparasites
 Closed circulatory systemClosed circulatory system
with hearts and bloodwith hearts and blood
vesselsvessels
 On land, annelidsOn land, annelids
breathe through theirbreathe through their
skin, like other wormsskin, like other worms

53. AnnelidaAnnelida
 Complex gutComplex gut
 GangliaGanglia
(primitive brain)(primitive brain)
and nerve chordand nerve chord

54. AnnelidaAnnelida
 Importance:Importance:
 Leeches once used toLeeches once used to
prevent swelling afterprevent swelling after
surgery.surgery.
 Earthworms helpEarthworms help
organic matterorganic matter
decompose and aeratedecompose and aerate
soil.soil.

55. MollusksMollusks
Phylum MolluscaPhylum Mollusca

56. Phylum MolluscaPhylum Mollusca

57. Kinds of MollusksKinds of Mollusks
 snails, slugs, clams,snails, slugs, clams,
oysters, mussels, scallops,oysters, mussels, scallops,
squids, octopi, cuttlefishessquids, octopi, cuttlefishes

58. Characteristics of MollusksCharacteristics of Mollusks
 Coelom!Coelom!
 Bilateral symmetryBilateral symmetry
 Soft-bodied (hydrostaticSoft-bodied (hydrostatic
skel.)skel.)
 Shell (internal orShell (internal or
external)external)

59. Bodies of Mollusks – 4 PartsBodies of Mollusks – 4 Parts
1.1. Foot (muscular,Foot (muscular,
used to move orused to move or
capture prey)capture prey)
2.2. Mantle (coversMantle (covers
body like a cloak)body like a cloak)
3.3. Shell (created fromShell (created from
glands in mantle)glands in mantle)
4.4. Visceral MassVisceral Mass
(contains organs)(contains organs)

60. Behavior of MollusksBehavior of Mollusks
 Feeding:Feeding:
 Filter feeders (bivalves)Filter feeders (bivalves)
 Carnivores (cephalopods)Carnivores (cephalopods)
 Herbivores (gastropods)Herbivores (gastropods)
 Toothed organ calledToothed organ called
RADULA used to scrapeRADULA used to scrape
substrate or attack preysubstrate or attack prey
 Full digestive tract withFull digestive tract with
complex organscomplex organs

61. Behavior of MollusksBehavior of Mollusks
 Nephridia = small tubesNephridia = small tubes
that retain neededthat retain needed
materials (like a kidney)materials (like a kidney)
 3-chambered heart3-chambered heart
 Open circulatory systemOpen circulatory system
(except for cephalopods)(except for cephalopods)

62. Behavior of MollusksBehavior of Mollusks
 Gills located in mantleGills located in mantle
cavitycavity
 Thin membrane ofThin membrane of
terrestrial snails allowsterrestrial snails allows
oxygen to pass acrossoxygen to pass across
 Must be moist!Must be moist!

63. Behavior of MollusksBehavior of Mollusks
 External fertilizationExternal fertilization
(aquatic) or internal(aquatic) or internal
fertilization (terrestrial)fertilization (terrestrial)
 Trochophore larvaeTrochophore larvae
drifts through waterdrifts through water
using ciliausing cilia

64. Mollusk DiversityMollusk Diversity
 22ndnd
-most abundant-most abundant
phylumphylum
 Body plan similar butBody plan similar but
rearrangedrearranged
 Adaptations to foot andAdaptations to foot and
shellshell

65. Class GastropodaClass Gastropoda
 Snails, slugs, nudibranchsSnails, slugs, nudibranchs
 Sizes to 1 mSizes to 1 m
 Tentacles with eyesTentacles with eyes
 Foot adapted forFoot adapted for
locomotionlocomotion
 Mucus secretionsMucus secretions

66. Class CephalopodaClass Cephalopoda
 squids, octopi, cuttlefishessquids, octopi, cuttlefishes
 Tentacles with suction cups orTentacles with suction cups or
hookshooks
 Most have no shellMost have no shell
 Complex nervous system; highly-Complex nervous system; highly-
developed braindeveloped brain
 Siphon – hollow tube forSiphon – hollow tube for
expelling sea water (locomotion)expelling sea water (locomotion)

67. Class BivalviaClass Bivalvia
 Clams, scallopsClams, scallops
 Two-part, hingedTwo-part, hinged
shellshell
 SessileSessile
 Foot used to digFoot used to dig
 PearlsPearls

68. ArthropodsArthropods
Phylum ArthropodaPhylum Arthropoda

69. Kinds of ArthropodsKinds of Arthropods
 crabs, shrimps, lobsters,crabs, shrimps, lobsters,
barnacles, horseshoebarnacles, horseshoe
crabs, spiders, ticks,crabs, spiders, ticks,
scorpions, bees, wasps,scorpions, bees, wasps,
ants, caterpillars,ants, caterpillars,
butterflies, beetles, flies,butterflies, beetles, flies,
gnats, cicadas, pillbugs,gnats, cicadas, pillbugs,
centipedes, millipedescentipedes, millipedes

70. Ecology of ArthropodsEcology of Arthropods
 73% OF ALL LIVING73% OF ALL LIVING
ANIMAL SPECIESANIMAL SPECIES
ARE INSECTSARE INSECTS
(compared to 4%(compared to 4%
vertebrates)vertebrates)
 To colonize land, insectsTo colonize land, insects
must solve problems of:must solve problems of:
 Transportation
 Water loss prevention
 Protection

71. Evolution of ArthropodsEvolution of Arthropods
 Over time, arthropodsOver time, arthropods
evolved fewer bodyevolved fewer body
segments and specializedsegments and specialized
appendagesappendages
 Trilobite – marineTrilobite – marine
arthropod ancestorarthropod ancestor

72. Arthropod Characteristics
 Segmented Body
 Greater number of
segments during larval
stage
 Adult: Head, thorax, (or
cephalothorax) and
abdomen
 Jointed Appendages
 Walking legs, antennae,
mouth parts

73. Arthropod Characteristics
 Exoskeleton of chitin
 Carbohydrate
 Protection / water loss
 Thickness varies
 Unlike mollusk shells,
exoskeletons do not grow
(must be molted)
 Compound Eyes

74. Arthropod Body Systems
 Respiration
 Spiracles can be closed (to
prevent water loss)
 System of tubes called
trachea
 Book lungs/gills
 Open circulatory system

75. Arthropod Body Systems
 Varied mouthparts for eating
(fly, beetle, mosquito)
 Complete gut
 Excretion
 Malpighian tubules extract water
and useful particles before waste
is excreted
 Internal fertilization and eggs
(water loss)

76. Classification of ArthropodsClassification of Arthropods
 CrustaceaCrustacea
 ChelicerataChelicerata
 HexapodaHexapoda
 MyriapodaMyriapoda

77. Chelicerates
 Spiders, horseshoe crabs,
scorpions, ticks, mites
 Specialized appendages for
feeding:
 Chelicerae – fangs/pincers
 Pedipalps – for grabbing prey
 Additionally, 4 pair of
walking legs

78. Chelicerates
 Toxins and enzymes used
to kill/liquefy food
 Spiders have spinnerets,
appendages that secrete
silk or adhesive
 Scorpions have
segmented abdomen
with a stinger

79. Crustaceans
 Water fleas, barnacles, pill
bugs, shrimp, crabs,
lobsters
 Mandibles for feeding;
two pair of antennae
 Mostly aquatic

80. Crustaceans
 Tiny krill are important in
food chains
 Barnacles are sessile (larvae
are not) and feathery legs
filter food into mouth
 Decapods (crabs, shrimp)
have chelipeds to grab food
and swimmerets used in
swimming and reproduction

81. Hexapods (Insects)
 3 segments
 3 pair of legs
 0, 1, or 2 pair of wings
 Varied mouthparts with
mandibles

82. Hexapods
 Wings of chitin and strong muscles in exoskeleton

83. Hexapods
 Metamorphosis
 Complete: egg  larva
 pupa  adult
 Incomplete: egg 
nymph  adult
 Advantages?

84. Myriapods
 Millipedes and
centipedes – highly
segmented
 Up to 200-300 legs!

85. EchinodermsEchinoderms
Phylum EchinodermataPhylum Echinodermata

86. Characteristics of EchinodermsCharacteristics of Echinoderms
 Internal (endo)skeletonInternal (endo)skeleton
 Water vascular systemWater vascular system
and tube feetand tube feet
 Often have pentamerousOften have pentamerous
symmetrysymmetry
 Types: sea urchins, sandTypes: sea urchins, sand
dollars, sea stars, brittledollars, sea stars, brittle
stars, sea cucumbersstars, sea cucumbers

88. EchinodermsEchinoderms
 Endoskeleton platesEndoskeleton plates
called ossiclescalled ossicles
 Spines project outwardSpines project outward
 No head/brain (notNo head/brain (not
cephalized)cephalized)
 Nerve ring controls armsNerve ring controls arms

89. Behavior of EchinodermsBehavior of Echinoderms
 Water vascular systemWater vascular system
functions in feeding,functions in feeding,
circulation, respiration,circulation, respiration,
and movementand movement
 Tube feet (suction cups)Tube feet (suction cups)
used to move or grabused to move or grab
 Sea stars can pry openSea stars can pry open
clams and mollusksclams and mollusks

90. Echinoderms – Tube FeetEchinoderms – Tube Feet

91. EchinodermsEchinoderms
 Coelom alsoCoelom also
functions asfunctions as
circulatorycirculatory
systemsystem
 RespirationRespiration
across skinacross skin

92. Phylum ChordataPhylum Chordata